1. Field of the Invention
This invention relates generally to article handling apparatus of the type employed in the transferral of open mouth containers, such as jars, from a shipping carton or case to an appropriate receiving station associated with a conveyor or the like in what may be referred to as a carton unloading operation. More particularly, the invention relates to the individual jar pick up means or assembly, of which there is one for each jar of a case, carried by a transfer head of the apparatus which operate to grip the respective jars so as to enable the jars to be picked up or lifted vertically out of the case during the course of an unloading operation.
A shipping case or carton of jars to be unloaded may contain twenty four or more jars which are normally arranged upright in side-by-side relation to each other and in rows with a typical twenty four jar carton presenting a four by six array. When in the carton the jars are closely packed and separated from one another only by case dividers of relatively thin material such a corrugated board or the like which prevents contact between the jars and possible damage thereto during shipment and handling. In unloading such a case of jars, simultaneously, by apparatus operating at high speeds, it is important that the jars which now no longer have dividers between them be held in a stable aligned relationship to the pick-up head with sufficient firmness as to prevent a jar from hitting or contacting an adjacent jar and causing possible damage thereto.
This problem is especially serious in instances where wide mouth jars are involved because due to the closeness of the neck or finish of a wide mouth jar to that of an adjacent jar contact between jars at the finish is possible, and any such contact or impact which resulted in a crack or chip at the threaded neck portion would render the jar defective since it would be unable to maintain a proper seal. This problem would not be as prevalent if it were feasible to provide jar gripping means which engage the outer surface of the neck or finish portion of thejar, but in the case of wide mouth jars the spacing between adjacent jars is limited thereby rendering it practically necessary to grip the jar on the inside surface thus exposing the outer surface of the threaded neck or finish to damaging contact with an adjacent jar. It is to the solution of this problem involved in the unloading of wide mouth jars that the present invention is directed.
2. Discussion of the Prior Art
U.S. Pat. No. to Rowekamp 3,075,800 discloses a jar pick up assembly of a type for which the present invention is adaptable. The device of this patent employs a pair of pivotally mounted pick up fingers which are rockable from a closed retracted position to an open expanded position. The fingers depend from the assembly and are lowered into the mouth of a jar when in the closed retracted position. Once in the jar and below a bead on the interior surface thereof, the fingers are opened or expanded into frictional contact with the interior jar wall. As the assembly is then lifted the fingers eventually engage the interior bead and lift the jar vertically out of the case or carton. The jar in effect rests on a surface portion of the fingers and is subject to tilting, rocking or axial displacement for whatever reason since it is not firmly gripped or clamped by mechanism operating in conjunction with the fingers to maintain jar stability and orientation by firmly gripping it in a clamp like manner.
U.S. Pat. No. to Haverbusch 4,173,368 discloses another pick up assembly for use with wide mouthed jars and employing a plurality of flexible straps which when longitudinally extended are lowered into the mouth of a jar and then are longitudinally contracted causing them to flex outwardly and in so doing frictionally engage the interior surface of the jar. The jar is supported merely by frictional resistance supplied by the expanded straps, and it is not gripped in the manner of a clamp so as to hold it firmly stable and in properly aligned relation to the pick-up head.
U.S. Pat. No. to Krupp, et al., 2,818,987 discloses a somewhat similar pick up assembly utilizing a flexible rubber cup which in the longitudinally extended condition is inserted into the mouth of a jar. Thereafter, the cup is longitudinally contracted causing the side walls thereof to bulge outwardly and make frictional contact with the interior surface of the jar. There is no means provided cooperating with the cups of gripping the jar in a clamp-like manner.
U.S. Pat. No. to Brubaker, 3,314,714 discloses a jar holder which employs a plurality of flexible fingers circumferentially arranged and adjusted so as to define a circumferential pattern having a diameter slightly larger than that of the mouth of the jar. The fingers are forced through the mouth of the jar which is accomplished by the inward flexing thereof, and once inside the jar they expand to their preset condition into frictional engagement with the interior surface of the jar. The jar is merely supported frictionally by said fingers, and although there is a cover member which is brought into contact with the top surface or finish of the jar, it merely rests thereon and does not perform any gripping or clamping function in cooperation with the fingers. Moreover, there is no means shown for automatically retracting the fingers within the jar to enable easy disengagement of the device from the jar, which disengagement can only be accomplished by again forcing the fingers through the smaller dimensioned mouth of the jar. The jar must be held by hand or some other means in order for the fingers to be withdrawn therefrom.
U.S. Pat. No. to Manganelli, 3,977,687 discloses a holder for hollow cylindrical articles which includes a plurality of resilient fingers which are able to receive a container when presented thereto in slightly misalignment and to support said container in proper aligned and stable position when fully seated thereon. The device does not lift the container nor does it have means for retracting and extending said fingers nor does it grip the container in a clamp-like manner.